Author: Mike Hotka

Presentation

“Is our Solar System Unique? A Holistic View of Exoplanet Demographics” by Dr. BJ Fulton

Summary

NASA’s Kepler and K2 missions discovered thousands of planets by watching for tiny dips in starlight when planets crossed in front of their stars. These discoveries let us study how planet sizes are distributed across the galaxy. Using precise measurements of the host stars we found a surprising gap between planets about 1.5 and 2 times the size of Earth. This “radius gap” suggests that small, close-in planets are rocky worlds with thin envelopes of gas that determine their overall size. Dr. Fulton will discuss what this means for how planetary systems form, and share related work on the abundance of giant planets orbiting far from their stars and the colder, darker regions of extrasolar systems. Combining results from Kepler and long-term, ground-based radial-velocity surveys gives us the most complete picture yet of planetary systems across a huge range of sizes and distances — and helps us ask whether our own solar system is typical or atypical in our galaxy.

Bio

Dr. Fulton is currently a research scientist at the NASA Exoplanet Science Institute (NExScI). He obtained M.S. and PhD degrees in astronomy from the University of Hawaii at Manoa and a B.S. in Physics from the University of California, Santa Barbara. Dr. Fulton specializes in building the software that enables the detection and characterization of planets orbiting stars other than our Sun (exoplanets) using Doppler spectroscopy. He is currently working remotely and lives in Estes Park, CO with his wife Amanda, their Dachshund, and two cats. Besides discovering alien worlds, Dr. Fulton enjoys digital photography and racing his Porsche at autocross and track events.

Title:

Amateur Observations of Jupiter’s Clouds, Hazes, and Composition

Summary:

Jupiter displays multiple colorful cloud types, with regional variations that change over time. For more than a century amateurs have observed and tracked these features, first visually, and now with sophisticated color cameras. These observations have provided the basis for understanding the circulation and wind patterns of the atmosphere, along with periodic regional and global upheavals. Amateurs now peer into the near-infrared (NIR), including the 889 nm methane band, and near ultraviolet (NUV) revealing details of upper-level hazes. Use of other methane filters can probe different cloud levels below the hazes. My recent work has added another twist: the ability to detect not just cloud height, but ammonia concentration. The question arises: How can amateurs contribute objective measurements of Jupiter’s clouds and their changes? By applying calibration to existing and new filter bands that are readily available from optical companies, amateurs can make quantitative measures of color, cloud height, and ammonia distribution. This talk provides background on Jupiter’s cloud layers, then describes these low-cost, accessible observing techniques, some of the results they’ve generated, and how they relate to and support professional planetary research.

Bio

Steven Hill is an amateur astronomer living in Denver where he enjoys the 300 sunny days and clear nights per year we get here in Colorado. Light pollution in the city of Denver led him to focus on bright objects like the planets. He recently retired from his day job at NOAA working on space weather observations. Steve has a Ph.D. in astrophysics, which helps him in all his space-related pursuits. With this background he likes to push the boundaries of what can be accomplished with his backyard telescope equipment. These factors all came together, leading him to investigate ammonia on Jupiter.

Location

The meeting will be at the First Evangelical Lutheran Church, 803 Third Avenue, Longmont, CO 80501.